[Skip to Content]
[Skip to Content Landing]

Point-of-Care Hemoglobin A1c

Educational Objective
To understand how to interpret the results of diagnostic tests and apply them clinically.
1 Credit CME

A 57-year-old white man with obesity and hypertension presents for a primary care visit, during which he expresses concern about having diabetes. He reports no symptoms of hyperglycemia, such as frequent urination, increased thirst, fatigue, or visual changes, and had no known family history of diabetes. A series of blood tests had recently been obtained (Table). His body mass index (BMI) is 33.9 and his blood pressure is 160/90 mm Hg. The patient wants to know if a test could be done in the office to determine if he has diabetes.

Please finish quiz first before checking answer.

You answered correctly!

Read the answer below and download your certificate.

You answered incorrectly.

Read the discussion below and retake the quiz.

C. Perform a laboratory-based HbA1c test to determine the patient’s glycemic status.

Hemoglobin A comprises approximately 97% of total hemoglobin and undergoes glycation with the nonenzymatic attachment of a sugar to its amino groups. Hemoglobin A1c (HbA1c) has glucose attached to the N terminus of β chains. The quantity of HbA1c is directly related to the glucose concentration that erythrocytes are exposed to over their life span, making HbA1c a clinically useful measure of mean glycemia during the preceding 3 months. Type 2 diabetes is defined by an HbA1c value of at least 6.5%, and prediabetes is defined by an HbA1c value of 5.7% to 6.4%. Individuals with prediabetes have an increased risk of developing type 2 diabetes, estimated at 5% to 10% annually and 70% in a lifetime.

Survey Complete!

Sign in to take quiz and track your certificates

Buy This Activity

JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 CME Credit™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC

Article Information

Corresponding Author: Matthew J. O’Brien, MD, MSc, Northwestern University, Feinberg School of Medicine, 750 N Lake Shore Dr, Sixth Floor, Chicago, IL 60611 (matthew.obrien1@northwestern.edu).

Published Online: September 12, 2019. doi:10.1001/jama.2019.14063

Conflict of Interest Disclosures: Dr O’Brien reported receiving support from the National Institute of Diabetes and Digestive and Kidney Diseases (R21-DK112066) and personal fees from Novo Nordisk. Dr Sacks reported receiving support from the National Institutes of Health Clinical Center Intramural Program and grants from the National Institutes of Health and serving as the chair on the National Glycohemoglobin Standardization Program steering committee.

Additional Contributions: We thank the patient for providing permission to share his information.

References
1.
American Diabetes Association.  2. Classification and diagnosis of diabetes: standards of medical care in diabetes-2019.  Diabetes Care. 2019;42(suppl 1):S13-S28. doi:10.2337/dc19-S002PubMedGoogle ScholarCrossref
2.
Whitley  HP, Yong  EV, Rasinen  C.  Selecting an A1C point-of-care instrument.  Diabetes Spectr. 2015;28(3):201-208. doi:10.2337/diaspect.28.3.201PubMedGoogle ScholarCrossref
3.
Lenters-Westra  E, Slingerland  RJ.  Three of 7 hemoglobin A1c point-of-care instruments do not meet generally accepted analytical performance criteria.  Clin Chem. 2014;60(8):1062-1072. doi:10.1373/clinchem.2014.224311PubMedGoogle ScholarCrossref
4.
Hirst  JA, McLellan  JH, Price  CP,  et al.  Performance of point-of-care HbA1c test devices: implications for use in clinical practice: a systematic review and meta-analysis.  Clin Chem Lab Med. 2017;55(2):167-180. doi:10.1515/cclm-2016-0303PubMedGoogle ScholarCrossref
5.
Nathan  DM, Griffin  A, Perez  FM, Basque  E, Do  L, Steiner  B.  Accuracy of a point-of-care hemoglobin A1c assay  [published online April 3, 2019].  J Diabetes Sci Technol. doi:10.1177/1932296819836101PubMedGoogle Scholar
6.
Little  RR, Rohlfing  C, Sacks  DB.  The National Glycohemoglobin Standardization Program: over 20 years of improving hemoglobin A1c measurement.  Clin Chem. 2019;65(7):839-848. doi:10.1373/clinchem.2018.296962PubMedGoogle ScholarCrossref
7.
Siu  AL; U S Preventive Services Task Force.  Screening for abnormal blood glucose and type 2 diabetes mellitus: U.S. Preventive Services Task Force recommendation statement.  Ann Intern Med. 2015;163(11):861-868. doi:10.7326/M15-2345PubMedGoogle ScholarCrossref
8.
Sacks  DB.  A1C versus glucose testing: a comparison.  Diabetes Care. 2011;34(2):518-523. doi:10.2337/dc10-1546PubMedGoogle ScholarCrossref
9.
Ziemer  DC, Kolm  P, Weintraub  WS,  et al.  Glucose-independent, black-white differences in hemoglobin A1c levels: a cross-sectional analysis of 2 studies.  Ann Intern Med. 2010;152(12):770-777. doi:10.7326/0003-4819-152-12-201006150-00004PubMedGoogle ScholarCrossref
If you are not a JN Learning subscriber, you can either:
Subscribe to JN Learning for one year
Buy this activity
jn-learning_Modal_LoginSubscribe_Purchase
If you are not a JN Learning subscriber, you can either:
Subscribe to JN Learning for one year
Buy this activity
jn-learning_Modal_LoginSubscribe_Purchase
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right

Name Your Search

Save Search
With a personal account, you can:
  • Track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
jn-learning_Modal_SaveSearch_NoAccess_Purchase

Lookup An Activity

or

My Saved Searches

You currently have no searches saved.

With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right
Topics
State Requirements